PROGRESS IN THE APPRAISAL OF SURFACE-TOPOGRAPHY DURING THE 1ST HALF-CENTURY OF INSTRUMENT DEVELOPMENT

The principal developments in the stylus measurement of roughness texture are traced. The instrument problems which were encountered, particularly with regard to the requirements of transmission characteristics and reference lines, are outlined. The behaviour of the skid is given further consideration, and a distinction is drawn between the systematic error resulting from its application to instrument calibration specimens and the random error to be expected from all kinds of workpieces. Brief consideration is then given to the development of roundness measurement and the requirements for avoiding excessive eccentricity distortion. Finally attention is drawn to some unfortunate anomalies that have arisen. © 1979.